<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>测试iframe</title>
  </head>
  <body>
    <h3>测试iframe</h3>
    <iframe src="about:blank" title="iframe Example 1" width="400" height="300"></iframe>

    <script>
      window.addEventListener("message", receiveMessage, false);

      function receiveMessage(event) {
        var origin = event.origin;
        if (origin !== "http://example.org:8080") {
          return;
        }
      }
    </script>
  </body>
</html>
